US1339684A

US1339684A - Slime-pulp thickener

Info

Publication number: US1339684A
Application number: US256968A
Authority: US
Inventors: Allen Charles
Original assignee: Individual
Current assignee: Individual
Priority date: 1917-06-09
Filing date: 1918-10-05
Publication date: 1920-05-11
Anticipated expiration: 1937-05-11
Also published as: US1350204A; US1360703A

Description

C. ALLEN.

SLIME PULP THICKENER.

APPLICATION FILED OCT. 5. 191a.

Patentd May 11,1920.

UNITED STATES lAIENT OFFICE.

CHARLES ALLEN, or EL Peso, TEXAS.

SLIME-PULP rnrcxnnna.

Specification of Letters fit'ent.

Patented May 11, 1920;

Original application filed June 9, 1917, Serial No. 173,785. Divided and this application filed. October 5, 1918. Serial No. 256,968.

To all whom it may concern: I

Be it known that I, CHARLES ALLEN, a citizen of the United States, residin at El Paso, in the county of El Paso and tate of Texas, have invented new and useful Improvements in Slime-Pulp Thickeners, of which the following is a specification.

This invention relates to a device for thickening slime or pulp, and particularly pertains to a structure similar to that disclosed in my co-pending application entitled, Slime pulp thickener, Serial Number 17 3,785, filed June 9, 1917, and of which the present application is a division.

Thickening, which is a partial dcwatering of finely divided solids in suspension, is almost universally used in the treatment of ores by wet milling processes, and in its every application it is of prime importance that the degree of thickeningbe uniform, that is, that the discharge of the thickened slime be always of the same density. Thickeners heretofore used depend upon the volume of pulp fed to the cone or tank for regulation of the size of the discharge orifice. The results are very unsatisfactory, inasmuch as the proportion of liquids to solids in the material discharged varies with the volume of slime pulp fed to'the' thickener.

In the present invention, the volume of slime pulp in the thickener in no manner alters the proportion of liquids tos'olids in the products discharged, within the limits of the capacity of the machine. The degree of thickeningis controlled, and for whatever degree of thickening the device is adjusted, that degree of thickening is auto matically maintained.

In slime pulp, the finely divided solids move freely without appreciably affecting the fluidity by friction among themselves. Such a pulp has the properties of a liquid so long as the solids are kept in suspension. WVhen the pulp is composed of Water and solid particles of greater specific gravity than water, the specific gravity of the pulp increases with all increases in the quantity of solids in suspension in the pulp. This pulp may thereforebe considered as a liquid of greater density than water. 7

In my invention I employ tw'o connected compartments having in one compartment a liquid, and in the other a mixture of liquid and solids or pulp. The variations in the density of the pulp,- due to the presence launder 1 2 is arranged around the top of'more or less solids in suspension, act to raise and lower the column of liquid, which column ofliquid carries a float operativcly connected to a valve at the bottom of the tank controlling the discharge orifice. When the pulp attains a certain density the valve is automatically openedto permit the discharge of the thickened pulp through the vmains practically constant. This is the reverse of the thickeners ordinarily used in which the volume of thickened slime discharged remains constant while the density of the discharge varies with the quantity fed into the thickener.

The invention is illustrated by way of example in the accompanying drawing in which the figure discloses the complete apparatus, as seen in central, vertical section.

Referring more particularly to the drawing, the apparatus is shown as comprising a tank 10 in the shape of an inverted cone having a discharge orifice 11 at its bottom for carrying off the thickened product. A of the tank. for carrying ofli' clear liquid which overflows the rim of the tank. A conduit 18 is provided to supply slime pulp to the center of the tank. The outlet 11 of the tank is indirectly opened and closed by a float 14 having variable buoyancy due to the application of adjustable weights 15. This ,float is providedwith operable connections 16 which extend downwardly and engage the and further extends downwardly to a level below the rim of the tank. This chamber is supplied with clear water through an in let supply pipe 19. The annular passageway of the chamber 18 is formed with openings in its bottom which are providod with tubular connecting elements 20 extending downwardly and communicating with a bell 21. This bell is in the shape of a cone terminating with a cylindrical lower portion.

The apex of the cone portion of the bell is in vertical alinement with the outlet opening of the conduit 13, and is also in concentric alinement with the vertical axis of the tank. The lower opened end of the bell is partially closed by means of an inverted conical shell 22, which is held with its base portion in spaced relation to the lower marginal edge of the bell 21 and allows a limited circulation of liquid through this opening to the bell. The downwardly projecting apex 22 of the shell 22 is in vertical alinement with the outlet orifice 11, thus the shell provides a throat of uniform cross section along which the pulp may pass to the orifice. The chamber 18 which communicates with the bell 21 through the passages 20 constitutes one of the connected compartments of which the tank with its pulp forms the other arms. These two compartments or communicating conduits are 'so arranged that a hydrostatic balance is established between the column of clear water on the one hand and the pulp on the other.

The variations in the density of the pulp outside of the float chamber act to vary the height of the column of water within the chamber, and will thereby directly produce a raising or lowering of the float, and through this action open or close the discharge orifice.

In the present instance the actuating force is the difference in the density of the contents of the tank and the contents of chamber 18, which to maintain a hydrostatic balance, raises the surface of the liquid in the conduit containing the liquid of lesser density above the level of the surface in the conduit containing the material of greater density. This difference of level is directly proportionate to the difference in the densities of the liquids. If it is assumed that the tank is filled with water as well as the chamber 18, the vertical length of the columns in both cases would be the same; if, without altering the length of the column, the density of the contents of one liquid column of the apparatus be increased, say one-tenth, then to maintain a hydrostatic balance, the length of the opposing column must be increased one-tenth. Applying this tothe device here shown, the portion of the tank 10 above the lower end of the bell 21 will represent one liquid column of the apparatus, and the chamber 18 and the bell 21 with the connecting elements 20 represent containing the thickened slime, as considered from the bottom of the bell as a base and directly in proportion to the excess in density of the contents of the tank over that of the contents of the float chamber and the associate parts.

Assume this difference in the density of the liquids in the two columns to be 0.25 and 8 the length of both columns when occupied by a liquid of the same density to be 25 inches, then the difference in the length of the two columns would be 6.25 inches. To prepare the device for operation, the cham- 9 ber 18, the bell 21 and the tank 10 are filled with clear water which may be admitted through the pipe 19. The slime pulp to be thickened is then admitted to the tank through the conduit 13, and as the liquid 9 contents of the tank overflow the rim thereof, the thickening process will take place. If, during the operation the liquid contents of'the bell 21 should not remain as free as might be desired from the solid particles in suspension, this liquid may be replaced by clear water through the pipe 19 without interrupting the operation of the apparatus. If desired, there may be a continuous flow of water from the supply pipe 19 into the 1 float chamber.

In order that the condition of the liquid in the chamber 21 may be ascertained, a tap pipe X is provided to extend through the side wall of the tank and through the hell 1 21. The cone shaped baflie 22 confines the downward flow of the thickened slime to an annular space within the tank and prevents a rapid downward movement of the slime directly above the discharge orifice 11, thus relieving the slime from objectionable agitation which might produce a suction within the bell 21 to draw the clear water downwardly from the chamber 18, it being desir I able to maintain the liquid contents of the 1 bell 21 and the chamber 18 in substantially a state of rest.

Itwill thus be seen that an apparatus is here provided which will automatically, operate to maintain the slime at a uniform density, saidoperation being dependent upon the foregoing specification that these terms include any other liquid or solution employed in practical milling operations.

While I have shown the preferred form of my invention as now known to me, it is understood that various changes may be made in the combination, construction and arrangement of parts without departing from the spirit of the invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is- 1. In a thickener for slime pulp, a settling tank having a controllable orifice for the discharge of thickened material, a fluid column in hydrostatic balance with the thickening material and adapted to contain fluid of fixed density whereby variations in the density of the thickening material will cause a change in the elevation of the fluid in said column, means actuated by the rise and fall of the height of the fluid in said column to control the sizes of the discharge orifice and a cone-shaped baffle member at the bottom of the fluid chamber overlying the discharge orifice for the purpose mentioned. p

2. A thickener for slime pulp, comprising a tank, an orifice at the bottom thereof, a valve for controlling the same, an inverted bell within the tank, an annular float chamber above the bell, a central passageway through which slime pulp may be fed into the tank, a float within said chamber, operating connections between the float and the valve, communicating passageways between the bell and the float chamber, whereby clear water positioned within the bell and chamber may stand in hydrostatic balance in relation to the pulp in the surrounding tank and will thus insure that variation in this hydrostatic balance will affect the float to accommodate the valve and thereby cause pulp of a predetermined density to be discharged from the tank.

3. A thickener for slime pulp, comprising a tank, an orifice at the bottom thereof, a valve for controlling the same, an inverted bell within the tank, an annular float chamber above the bell, a central passageway through which slime pulp may be fed into the tank, a float within said chamber, operating connections between the float and the valve, communicating passageways between the bell and the float chamber, whereby clear water positioned within the bell and chamher may stand in hydrostatic balance in re- I lation to the pulp in the surrounding tank and will thus insure that variation in this hydrostatic balance will affect the float to accommodate the valve and thereby cause pulp of a predetermined density to be discharged from the tank and an inverted conical shell disposed below the mouth of the bell and spaced in relation thereto to prevent undue agitation of the liquid within the bell.

4-. A thickener for slime pulp comprising an inverted conical tank, a launder around the rim thereof, a valve controlled discharge opening in the apex of said cone, a conical bell positioned within the tank and adapted to receive clear water, an inverted conical shell secured to said bell and held in spaced relation therebeneath, an annular float chamber positioned above the bell and in com- 'munication therewith, said chamber and bell being filled with clear water, a float within said chamber, means connecting with the float and adapted to control the orifice in the bottom of the tank, whereby variation in the hydrostatic balance between the pulp within the tank and the clear water within the bell will actuate said orifice controlling mechanism.

5. A thickener for slime pulp, comprising a tank, an orifice at the bottom thereof, a valve for controlling the same, an inverted bell within the tank, an annular float chamber above the bell, a central passageway through which slime pulp may be fed into the tank, a float within said chamber, oper ating connections between the float and the valve, communicating passageways between the bell and the float chamber, whereby clear water positioned within the bell and chamber may stand in hydrostatic balance in relation to the pulp in the tank and will thus insure that variation in this hydrostatic balance will affect the float to accommodate the valve and thereby cause pulp of a predetermined density to be discharged from the tank, and means whereby the water in said float chamber and inverted bell may be maintained in an uncontaminated condition. In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

CHARLES ALLEN. Witnesses:

O. A. GRITCH'ER, EDMUND SHAW.